title: Droplet evaporation and spread on waxy and hairy leaves associated with type and concentration of adjuvants.
abstract: BACKGROUND
  Adjuvants can improve pesticide application efficiency and effectiveness. However, quantifications of the adjuvant-amended pesticide droplet actions on foliage, which could affect application efficiencies, are largely unknown.
  
  
  RESULTS
  Droplet evaporation rates and spread on waxy or hairy leaves varied greatly with the adjuvant types tested. On waxy leaves, the wetted areas of droplets containing crop oil concentrate (COC) were significantly smaller than those containing modified seed oil (MSO), non-ionic surfactant (NIS) or oil surfactant blend (OSB), whereas the evaporation rates of COC-amended droplets were significantly higher. On hairy leaves, COC-amended droplets remained on top of the hairs without wetting the epidermis. When the relative concentration was 1.50, the wetted area of droplets with NIS was 9.2 times lower than that with MSO and 6.1 times lower than that with OSB. The wetted area increased as the adjuvant concentration increased. MSO- or OSB-amended droplets spread extensively on the hairy leaf surface until they were completely dried.
  
  
  CONCLUSIONS
  These results demonstrated that the proper concentration of MSO, NIS or OSB in spray mixtures improved the homogeneity of spray coverage on both waxy and hairy leaf surfaces and could reduce pesticide use. This article is a US Government work and is in the public domain in the USA.
authors.affiliation: The Ohio State University/OARDC, Wooster, OH, USA.
authors.forename: Linyun
authors.initials: L
authors.lastname: Xu
authors.forename: Heping
authors.initials: H
authors.lastname: Zhu
authors.forename: H Erdal
authors.initials: HE
authors.lastname: Ozkan
authors.forename: William E
authors.initials: WE
authors.lastname: Bagley
authors.forename: Charles R
authors.initials: CR
authors.lastname: Krause
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000737:chemistry* / Q000494:pharmacology; D002626:Chemistry, Pharmaceutical; D010316:Particle Size; D031316:Pelargonium / Q000737:chemistry / Q000187:drug effects; D018515:Plant Leaves / Q000737:chemistry* / Q000187:drug effects; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology; D013045:Species Specificity; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000277:Adjuvants, Pharmaceutic; D010938:Plant Oils; D013501:Surface-Active Agents